Problem: $9cd + 6d + 8e - 10 = 10d + 5e - 5$ Solve for $c$.
Answer: Combine constant terms on the right. $9cd + 6d + 8e - {10} = 10d + 5e - {5}$ $9cd + 6d + 8e = 10d + 5e + {5}$ Combine $e$ terms on the right. $9cd + 6d + {8e} = 10d + {5e} + 5$ $9cd + 6d = 10d - {3e} + 5$ Combine $d$ terms on the right. $9cd + {6d} = {10d} - 3e + 5$ $9cd = {4d} - 3e + 5$ Isolate $c$ ${9}c{d} = 4d - 3e + 5$ $c = \dfrac{ 4d - 3e + 5 }{ {9d} }$